Evaluating the short-term, preference-based, quality-of-life effects of radiologic tests has not been previously addressed. Robust evaluation of short-term utility could be an important factor in cost-effectiveness analyses of radiologic technologies, as well as providing important information to patients, the community at large, and health-care policy makers. Our aim in this project is to validate an original variation on time tradeoff (TTO) methodology for utility assessment, called the diagnostic TTO, or DTTO, which has been adapted for short in short-term health states. such as those seen in diagnostic radiology. We will assess utility for conventional x-ray angiography (XRA)versus MR angiography (MRA) for imaging atherosclerotic carotid vascular disease. The project will compare two groups of people: 1). A group of 100 healthy students, who will be informed on the facts of carotid vascular disease as well as the MRA and XRA techniques, and then interviewed with multi-attribute methods to evaluate the influence of variables on their utility for XRA and MRA, as measured by the DTTO. Such variables might include degree of discomfort of the test, duration of time with disease before seeking treatment, current health state, anticipate future health state, and duration uncertainty of future health state. 2) A group of 100 patients enrolled in a multi-institutional study of MRA for the evaluation of carotid atherosclerotic vascular disease. Actual information relative to the variables mentioned above will be gathered for each patient. A rating scale technique will be used a check on the direction of preference given by DTTO. These two groups for study are representative of two different types of utility: remembered utility, which is appropriate to the patients experienced in a health state of interest, and predicted utility, which is appropriate to student subjects. These two types of utility are at the core of an ongoing controversy in medical economic analysis: should patient or non-patient utilities be used for reference analyses that may decide allocation of resources? This study will therefore evaluate the reliability of the DTTO technique, and will assess for differences in remembered and predicted utility. Of interest will be whether trends similar to those seen with long-term outcomes will be captured with this technique. The ultimate goal is to facilitate more accurate cost-effective analyses of radiologic technologies. This is very important to the filed of radiology where there are demands to prove the cost effectiveness of imaging, but no optimized model in place for accomplishing the task.